5V Oscillator Characteristics
22.7 5V Oscillator Characteristics
Table 22-6. Oscillator Specifications (5V)
Characteristic(1)
Symbol
Min
Typ
Max
Unit
88k(2)
fICLK
Internal oscillator clock frequency
64k
104k
Hz
External reference clock to OSC1(3)
fOSC
dc
32M
Hz
fXTALCLK
CL
Crystal reference frequency
Crystal load capacitance(4)
Crystal fixed capacitance(5)
30
—
32.768
12.5
15
100
—
kHz
pF
C1
—
—
pF
Crystal tuning capacitance(6)
Feedback bias resistor
Series resistor
C2
15
—
—
pF
RB
1
10
22
MΩ
kΩ
RS
100
330
470
fRCCLK
REXT
External RC clock frequency
RC oscillator external R
RC oscillator external C
7.6M
Hz
Ω
See Figure 22-1
10
CEXT
—
—
pF
1. The oscillator circuit operates at VREG
.
2. Typical value reflect average measurements at midpoint of voltage range, 25 °C only.
3. No more than 10% duty cycle deviation from 50%. The max. frequency is limited by an EMC filter.
4. Crystal manufacturer value.
5. Capacitor on OSC1 pin. Does not include parasitic capacitance due to package, pin, and board.
6. Capacitor on OSC2 pin. Does not include parasitic capacitance due to package, pin, and board.
MCU
C
V
= 10 pF
EXT
8
6
4
2
0
= 5V, @ 25°C
DD
OSC1
V
REG
R
C
EXT
EXT
0
10
20
30
(kΩ)
40
50
Resistor, R
EXT
Figure 22-1. RC vs. Frequency
MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor
301
FREESCALE [ Freescale ]
